New Species of Macroalgae from Tamengo Formation, Ediacaran, Brazil

The Tamengo Formation (Corumbá Group) is an important Ediacaran stratigraphic unit in South America due to the presence of metazoan fossils and geochemistry data of carbonate rocks, with excellent geochronological delimitation (between 555–541 Ma) obtained by U–Pb dating on volcanic zircons. The present work shows three new species of macroalgae found as carbonaceous compressions and studied for their morphology and taxonomy. All new taxa are characterized as centric macroalgae; Tamengophyton espinosa sp. nov. is a fan-shaped alga with striated thalli, dichotomous branches, trichomes with perpendicular growth, and a connecting membrane. Ladariella hidria sp. nov. is formed by a set of striated and branched thalli in a cylindrical form with almond-shaped structures in the top. Ladariophyton veinosa sp. nov. is characterized by the main growth thallus and an enlarged longitudinal structure at the center. These new occurrences of macroalgae add to the largest life assemblages in the Neoproterozoic of South America, which contributes to documentation of the evolutionary history of macroalgae and the paleoecological settings of the Late Ediacaran.

Investigation of the Ordered Structure in Partially Melted Isotactic Polypropylene

The ordered structure of partially melted isotactic polypropylene (iPP) was investigated using polarized optical microscopy (POM) and small-/wide-angle X-ray scattering (SAXS/WAXS) measurements. The crystalline morphology was first examined by means of pulling a glass fiber through the iPP melt, which was generated by partially melting a preformed spherulite. The results from the POM experiments indicated that, even at a minimal pulling rate, the surviving ordered structure could also relocate along the direction of fiber pulling and grow into cylindrites eventually. In addition, during the quiescent crystallization from the partially melted sample, which had the same thermal history of fiber-pulling experiments, the obvious memory effect of melt was also observed from the results of X-ray experiments. Moreover, the SAXS profile derived from the partially melted iPP at 170 °C was fitted by the theory of scattering amplitude with the cylindrical form factor. The fit result implied that the surviving ordered structure is of cylindrical nanocrystals with a diameter D ≈ 30 ± 3 nm and height h ≈ 45 ± 3 nm, which can significantly influence the crystallization morphology and kinetics during the subsequent crystallization process.

Influence of form and size of a root on the storage life of kitchen beetroot

Kitchen beetroots have a series of high-value parameters: good taste properties, healing-prophylactic importance, ability to long-term storage. There are many sorts of kitchen beetroot, different by root form. Most widespread are ones of the round and cylindrical forms. At the same time plants of kitchen beetroot at growing form roots of different masses. The aim of the study was to investigate the storage life of kitchen beetroot depending on form and root sizes. The conducted studies give a possibility to substantiate scientifically an influence of kitchen beetroots’ form and sizes on their storage life for determining its term. It has been established, that roots of the round form of the Kharkiv Bordo sort lost moisture more intensively at the expanse of breath and evaporation – 4.4–5.4 %. In the Vital sort with roots of the cylindrical form, mass natural losses were 4.1–5.1 %. At that more natural mass losses were in small roots with mass 150–300 g. Small roots were more inclined to sprouting at storage. Among sprouted roots, 1.6–1.8 % were small ones with mass 150–300 g. More percent of sprouted roots was for ones with mass 500–700 g as 2.3–2.5 %. At that less percent of sprouted roots was in the Vital sort of the cylindrical form. Small roots with mass 150–300 g were more damaged by rots at storage – 10.4–12.3 %. Among roots of middle sizes, 6.0–6.8 % were damaged by rots, among big ones – 4.5–4.7 %. It must be also noted, that cylindrical roots of the Vital sort were less damaged by rots at storage than round ones of the Kharkiv Bordo sort

The Word of God in One’s Hand: Touching and Holding Pendant Koran Manuscripts

Koran manuscripts that fit comfortably within the palm of one’s hand are known as early as the 10th century CE.For the sake of convenience, all dates will be given in the common era (CE) without further mention, and not in the Islamic or Hijra calendar. Their minute and sometimes barely legible script is clearly not intended for comfortable reading. Instead, recent scholarship suggests that the manuscripts were designed to be worn on the body like pendants or fastened to military flag poles. This is corroborated by some preserved cases for these books which feature lugs to attach a cord or chain, but also their rare occurrence in contemporary textual sources. While pendant Korans in rectangular codex form exist, the majority were produced as codices in the shape of an octagonal prism, and others as scrolls that could be rolled up into a cylindrical form. Both resemble the shapes of similarly dated and pre-Islamic amulets or amulet cases. Building on recent scholarship, I will argue in this article that miniature or pendant Koran manuscripts were produced in similar forms and sizes because of comparable modes of usage, but not necessarily by a deliberate imitation of their amuletic ‘predecessors’. The manuscripts’ main functions did not require them to be read or even opened; some of their cases were in fact riveted shut. Accordingly, the haptic feedback they gave to their owners when they carried or touched them was not one of regular books but one of solid objects (like amulets) or even jewellery, which then reinforced this practice.

Application of “flat’ closed-bottom submerged nuzzles for decreasing rejections of slabs because of longitudinal cracks

In the process of steel continuous casting it was discovered, that due to relatively small distance between a submerged nuzzle and a mold walls, formation of “scull crust” takes place in the area of small and big radius of the billet. It resulted in deterioration of heat-away in mold, conditions are formed for origination of longitudinal cracks following its further opening in the CCM secondary cooling zone. To decrease the number of rejections continuously casted slab billets due to existence of longitudinal cracks, it was proposed to use “flat” closed-bottom submerged nuzzles. It was shown, that in contrast to cylindrical form of a series closed-bottom submerged nuzzle, the proposed one has rectangular section with chamfered butt facet in the are of nuzzle submerging into the mold melt, which enables to ensure better fluidity of slag-forming mixture between the nuzzle and the mold walls. This effect results in onsiderable improving evenness of heat-away. To confirm the effectiveness of the pilot submerged nuzzles application, in 2019 their pilot-industrial tests were accomplished in the campaign of casting of carbon and peritectic steels to produce 200 mm thick slabs at CCM No. 4. In the process of the tests when casting various steels, the same slag-forming mixtures were used. As a result of the tests the decrease of rejections of continuously casted slabs due to longitudinal cracks formation was confirmed.

Adsorption of phosphate by halloysite (7 Å) nanotubes (HNTs)

The adsorption and retention of phosphates in soil systems is of wide environmental importance, and understanding the surface chemistry of halloysite (a common soil clay mineral) is also of prime importance in many emerging technological applications of halloysite nanotubes (HNTs). The adsorption of phosphate anions on tubular halloysite (7 Å) has been studied to gain a greater understanding of the mechanism and kinetics of adsorption on the surface of HNTs. Two well-characterized tubular halloysites with differing morphologies have been studied: one polygonal prismatic and one cylindrical, where the cylindrical form has a greater surface area and shorter tube length. Greater phosphate adsorption of up to 42 μmol g–1 is observed on the cylindrical halloysite when compared to the polygonal prismatic sample, where adsorption reached a maximum of just 15 μmol g–1 compared to a value for platy kaolinite (KGa-2) of 8 μmol g–1. Phosphate adsorption shows strong pH dependence, and the differences in phosphate sorption between the prismatic and cylindrical morphologies suggest that phosphate absorption does not occur at the same pH-dependent alumina edge sites and that the lumen may have a greater influence on uptake for the cylindrical form.

DOSE ESTIMATION OF THE BNCT WATER PHANTOM BASED ON MCNPX COMPUTER CODE SIMULATION

Cancer is a malignant tumor that destroys healthy cells. Cancer treatment can be done by several methods, one of which is BNCT. BNCT uses 10B target which is injected into the human body, then it is irradiated with thermal or epithermal neutrons. Nuclear reaction will occur between boron and neutrons, producing alpha particle and lithium-7. The dose is estimated by how much boron and neutron should be given to the patient as a sum of number of boron, number of neutrons, number of protons, and number of gamma in the reaction of the boron and neutron. To calculate the dose, the authors simulated the reaction with Monte Carlo N Particle-X computer code. A water phantom was used to represent the human torso, as 75% of human body consists of water. Geometry designed in MCNPX is in cubic form containing water and a cancer cell with a radius of 2 cm. Neutron irradiation is simulated as originated from Kartini research reactor, modeled in cylindrical form to represent its aperture. The resulting total dose rate needed to destroy the cancer cell in GTV is 2.0814×1014 Gy.s (76,38%) with an irradiation time of 1,4414×10-13 s. In PTV the dose is 5.2295×1013 Gy.s (19,19%) with irradiation time of 5.7367×10-13 s. In CTV, required dose is 1.1866×1013 Gy.s (4,35%) with an irradiation time of 2.5283×10-12 s. In the water it is 1.9128×1011 Gy.s (0,07%) with an irradiation time of 1,5684×10-10 s. The irradiation time is extremely short since the modeling is based on water phantom instead of human body.Keywords: BNCT, Dose, Cancer, Water Phantom, MCNPX

Carbon Nanotubes: A Brief Review on Its Use for Biomedical Imaging Purpose

Carbon nanotubes (CNTs) belong to the fullerene family, also known as graphene. These graphenes are similar to the graphite sheets and when these are turn up in the cylindrical form they are known as carbon nanotubes. Currently, the most common methods used for CNTs preparation are: Electric-arc-discharge methods, Chemical-vapor-deposition method and Laserablation method. In order to cross the cell membrane, functionalization of the pristine CNTs is performed. Because of the sp2 hybridization and closely packed hexagons in their structure, functionalization of the pristine CNTs can be done easily with either therapeutic agent or the imaging agent. They have wide applications in the field of bio-imaging because of their intrinsic optical, mechanical and electrical properties. They can be used as efficient contrast agents and the biosensors as well as efficient carriers for the delivery of therapeutic or imaging agents.

An Analytical Drain Current Model for Dual-material Gate Graded - channel and Dual-oxide Thickness Cylindrical Gate (DMG-GC-DOT) MOSFET

Background: A novel Dual Material Gate Graded Channel and Dual Oxide Thickness Cylindrical Gate (DMG-GC-DOT) MOSFET is presented in this paper. Methods: Analytical model of drain current is developed using a quasi-two-dimensional cylindrical form of the Poisson equation and is expressed as a function of the surface potential, which is calculated using the expressions of the current density. Results: Comparison of the analytical results with 3D numerical simulations using Silvaco Atlas - TCAD software presents a good agreement from subthreshold to strong inversion regime and for different bias voltages. Conclusion: Two oxide thicknesses with different permittivity can effectively improve the subthreshold current of DMG-GC-DOT MOSFET.